The incidence of various allergies and respiratory tract infections has strongly increased recently. This may easily have the result that a patient with a respiratory disease is subjected to continuous pharmacotherapy and repeated antibiotic regimes. These may have adverse effects and cause new problems. Mucus excreted in bronchitis and infection factors easily remain in obstructed small bronchial tubes and pulmonary alveoli, causing shortness of breath. Therefore, in practice, it is often difficult for inhaled drugs to have a strong effect on those areas of the respiratory organs where the actual therapy would be needed.
In obstructive pulmonary diseases, such as asthma and chronic obstructive pulmonary disease, the obstruction of the airways restricts the flow of air in strong exhalation. In asthma, the bronchial tubes are obstructed as a result of an inflammation, and in chronic obstructive pulmonary disease, the symptoms are caused by a long-lasting inflammation and obstruction of the pulmonary alveoli and by the stiffening of the thorax resulting from these. In obstructive pulmonary diseases, the symptoms include shortness of breath and mucus in the airways. Furthermore, the symptoms can be aggravated by thoracic muscle tension resulting from the diseases. Moreover, in acute respiratory tract infections, the bronchial tubes of the patients may easily become irritated and inflamed. In respiratory tract infections, coughing removes mucus and makes it rise higher from the bronchial tubes. In a patient with asthmatic symptoms, a respiratory tract infection contracts the bronchial tubes and thereby causes shortness of breath, and mucus cannot be sufficiently removed by coughing, wherein the mucus accumulates in the respiratory tract and increases the risk of catching e.g. pneumonia.
In the care of pulmonary diseases and respiratory tract infections, blowing into a bottle and steam inhalation have been used as non-pharmacological remedies at home. When blowing into a bottle, the patient blows through a hose into a bottle that contains water. Such resisted blowing removes mucus and opens bronchial tubes. Steam inhalation, in turn, moistens the bronchial tubes and makes the excreted mucus more fluid.
Pulmonary diseases increase cardiac loading and aggravate heart-related diseases, such as the occurrence of arrhythmias (for example, atrial fibrillation).
In the care of respiratory diseases and allergies, various inhalators and steam inhalers have been used for conveying water vapour to the lungs by inhalation. However, such devices and methods may involve the drawback that the temperature of the water vapour to be inhaled is too high, which may damage the respiratory organs and cause a risk of burn. Furthermore, if the aim is to use the water vapour for carrying a drug to the lungs, only part of this drug will end up in the lungs, because most of the water vapour is not inhaled but evaporated in the ambient air.
The publication WO 02/092157 discloses a portable medical gas humidifier, which may be used with portable sources of contained oxygen or other breathable gases. The device consists of a reservoir for water and connections from the source of breathable air (or gas) and to the patient's breathing device. When connected, all of the breathable air source (or gas) passes quietly through the reservoir and becomes “humidified”. The device is intended to humidify the air which a patient inhales. The humidifying is achieved by providing pressurized oxygen from the top of the device inside the reservoir containing water, wherein the oxygen is forced to the bottom of the reservoir and produces bubbles to moisturize the oxygen which the patient inhales. The pressure of the oxygen makes it easier for the patient to inhale i.e. the inhalation resistance is reduced when this device is used, wherein the pulmonary alveoli of the patient are not efficiently opened.
The publication CN 2297204Y discloses a breathing recovery exercising apparatus, which is composed of a container and a breathing tube which is communicated with the container. A baffle is arranged in the container and divides the container into an inhalation air chamber and an exhalation air chamber which are respectively provided with a pressure regulating air inlet tube and a pressure regulating air inlet tube. The breathing tube is formed into an inverted Y shape by an inhaling tube and an exhaling tube, in which non-return flaps are respectively arranged. The breathing recovery exercising apparatus has an exercising means with three functions of inhalation, exhalation, and combined inhalation and exhalation. The pressure in the inhalation air chamber is generated by an external pressure source. Therefore, the device cannot utilize the pressure of the exhalation air in the operation of the device. Furthermore, the positive effect that pulmonary alveoli of the user are opened more efficiently which strengthens the lungs and also improves the efficiency of inhalation is not achieved by the device of CN 2297204Y.
The publication GB1332382 discloses a device which may be adjusted to function as either a humidifier or an atomizer. The device comprises a chamber, a valve housing, an upper conduit and a lower conduit each of which communicates with a cavity formed in the valve housing. The lower conduit is also communicating with the chamber. The device also comprises a valve spool received in the cavity to define with the housing a valve chamber. When the device is used as a humidifier the valve spool is positioned to align passageways with the upper and lower conduits to allow air or oxygen to pass from the upper conduit to the lower conduit through the water in the chamber, and to a patient through a gas outlet tube. When the device is used as an atomizer a passageway of the valve spool is aligned with the upper conduit so that gas can pass from the upper conduit to the valve chamber through an orifice, and water can pass from the lower conduit to the valve chamber through a groove, the velocity of the gas through the orifice creating a vacuum in the valve chamber which draws the water into the chamber, and causing the water to break up into droplets to form an aerosol, which passes through the orifice and outlet tube to a patient. The device of GB1332382 may only be used during inhalation stage.